Burger King plans to go cage-free by 2017

Burger King plans to only use eggs that came from cage-free hens by 2017, the company announced in a press release today. The company said that, by 2017, it will also "only purchase pork from suppliers that can demonstrate documented plans to end their use of gestation crates for breeding pigs."

Because Burger King uses hundreds of millions of eggs and tens of millions of pounds of pork annually, its decision could cause major changes in the egg and pork industries, the Associated Press reported.

In 2007, when Burger King began using cage-free pork and eggs, it became the first major fast-food chain to incorporate animal welfare issues into its policies, according to the AP.

Farmers produce about 250 billion eggs per year in the United States, but only 4 percent of those eggs came from hens that were not kept in cages, the Wall Street Journal reported.

States such as Florida and California, however, already have laws that ban the use of small crates for meat and egg-producing animals, the Los Angeles Times reported.

According to the Mayo Clinic, cage-free eggs come from animals that are free to roam within an enclosed barn. However, cage-free hens still do not necessarily have access to the outdoors, and some controversial practices such as beak cutting are still allowed.

And, unlike organic eggs, which must come from hens that are not given hormones, drugs or antibiotics (unless they suffer a disease), according to CNN, there are no guidelines for how cage-free hens must be fed.